This invention relates to a method and an apparatus for the control of biological growth and by-products thereof in hydrocarbon distillates. More particularly, to control of microbiological growth and organic acids in liquid-fuel systems, particularly systems where the fuel is gasoline, including aviation gasoline, or diesel fuels.
There are species of Protista which grow, and under certain circumstances even flourish within fuels and lubricants derived from the hydrocarbon distillation process. These use the above-mentioned fuels and lubricants as their source of nutrition.
"Protista" as used herein includes all lower organisms, such as algae, bacteria, fungi, and protozoans. The growth of such Protista within feed lines of such fuel systems, or in storage portions of such fuel systems causes impairment of the system. Typical features are blocked feed lines and clogged fuel filters, and accelerated wear of, for example, injection equipment due to secreted organic acids.
The use of liquid-fuelled internal combustion engines is widespread. For example, much transport of goods and commerce relies on such engines for basic transport, but also in relation to such machines as hydraulic hoists, pumps, lifts and the like, and also in motors in heating and cooling systems. While the major problems of Protistal growth currenty relate principally to engines using automotive gas, oil (diesel) and kerosene (jet fuel), this invention is equally applicable to any unit using fuels/lubricants derived from the crude oil distillation process.
A typical example of problems involving cooling systems is provided by refrigerated containers. These are commonly supplied with a small cooling system utilizing a small internal combustion engine. The quality of the products transported in such containers, particularly food products, is dependent on the ability of the system to maintain a pre-selected temperature. The infestation of the fuel system with Protista decreases the efficiency of the system, occasionally to such a point that complete breakdown occurs.
Investigation into efficacious chemical additives for fuel systems to chemically control or eliminate the growth of these Protista continues, but the additives themselves may adversely affect the performance of the fuel, and do not deal with the accumulation of dead growth. In addition, it is a process entailing some considerable expense, and may require careful monitoring, or surveillance of chemical levels within the fuel itself. It is accordingly an object of this invention to provide an apparatus and a method for controlling Protistal growth and by-products thereof in hydrocarbon distillates, particularly in liquid fuels and lubricants.
It is a further object to provide an apparatus and a method for controlling Protistal growth which is simple to install, easy to maintain, and which has substantially no other effects upon the fuel or the fuel systems.
The use of magnetic fields for treatment of fluids is known, principally in relation to the removal of scale forming or corrosive materials from fluids. For example, New Zealand patents 172611, 94971, and 146614 deal with this aspect of magnetic treatment. In addition, the use of magnetic fields has been known in the treatment of fluids for removing ferromagnetic particles from fluids; New Zealand patent 156200 deals with this aspect of the use of magnetic fields.
The use of magnetic fields for inhibiting algae and bacteria in open, uncovered storage water is disclosed in New Zealand patent 182685.
However, there is in the prior art, no suggestion that the use of magnetic fields is efficacious in the control of Protista in distillates. The applicant has determined that magnetic fields are particularly effective, when applied to Protista in distillates, in inhibiting growth of such Protista. Further, the applicant has discovered that the magnetic fields may be applied to the fuel either between pumping from storage to holding tanks, or between holding tanks and the combustion engine or in bulk storage.